High responsivity thermochromic infrared detector

Abstract

A high responsivity thermochromic infrared detector which has an operating temperature that is established on the steepest part of the phase transition curve and is maintained there while the infrared detector is operated.

What is claimed is: 
     
       1. An infrared radiation detector comprising, in combination: a thermochromic detector array comprised of a thermochromic material attached to a semiconductor body in a manner effective to provide thermal isolation therebetween, said thermochromic material having a phase transition curve representing bulk material resistivity (ω.cm) of said thermochromic material as a function of material temperature, wherein said thermochromic material is present at an operating temperature at a location of steepest slope of said phase transition curve;   a thermoelectric heater/cooler device on which said thermochromic detector array is mounted, wherein said thermoelectric heater/cooler device maintains said operating temperature of said thermochromic material at said location of steepest slope of said phase transition curve of said thermochromic material.   
     
     
       2. The infrared detector of claim 1, wherein said thermochromic material is selected from the group consisting of polycrystalline vanadium dioxide and monocrystalline vanadium dioxide. 
     
     
       3. The infrared detector of claim 2, wherein said vanadium dioxide has a film thickness of about 250 to 2500 Å and a resistivity of about 5×10 -2  ohm.cm at 68° C. 
     
     
       4. The infrared detector of claim 1, wherein said semiconductor body is monocrystalline silicon. 
     
     
       5. The infrared detector of claim 1, wherein said thermochromic material comprises V 4  O 7  and said operating temperature is about -25° C. 
     
     
       6. The infrared detector of claim 1, wherein said thermochromic material comprises V 2  O 3  and said operating temperature is about -127° C. 
     
     
       7. The infrared detector of claim 1, wherein said thermochromic material comprises V 2  O 2  and said operating temperature is about -147° C. 
     
     
       8. The infrared detector of claim 1, further comprising a multiplexer selected from the group consisting of silicon and GaAs, and bump interconnections present between said thermochromic detector and said multiplexer. 
     
     
       9. The infrared detector of claim 1, wherein said thermochromic detector is connected to a multiplexer chip by wires or is ribbon bonded to said multiplexer chip by a wire bonding method selected from the group consisting of ball bonding, chisel bonding, and ribbon methods. 
     
     
       10. The infrared detector of claim 1, wherein said thermochromic material is selected from the group consisting of VO 2 , V 2  O 3 , V 4  O 7 , V 2  O 2 , Ag 2  S, and VO x  where x≦2. 
     
     
       11. An infrared radiation detector comprising, in combination: a thermochromic detector array comprised of a thermochromic material attached to a semiconductor body in a manner effective to provide thermal isolation therebetween, said thermochromic material having a phase transition curve representing bulk material resistivity (ω.cm) of said thermochromic material as a function of material temperature, wherein said thermochromic material is present at an operating temperature of within ±0.5° C. of a location of steepest slope of said phase transition curve;   a thermoelectric heater/cooler device on which said thermochromic detector array is mounted, wherein said thermoelectric heater/cooler device maintains said operating temperature of said thermochromic material at within ±0.5° C. of said location of steepest slope of said phase transition curve of said thermochromic material.